Electrofilters



, lApril 2.8, 1959 s, 'MATTs ELECTROFILTERS 2 shets-'sheet 2 Filed Oct. 2, 1.956'

l m [E LL INVNTQR: SIGVARD MATTS United States Patent ELECTROFILTERS Sigvard Matts, Jonkoping, Sweden, assignor to AB Svenska Flaktfabriken, Stockholm, Sweden Application October 2, 1956, Serial No. 613,506 Claims priority, application Sweden October 27, 1955 4 Claims. (Cl. 183`7) When cleaning gases by means of electrolters it is of great importance that the dust precipitated on the collecting electrodes be removed from the gas current without any substantial part thereof being picked up again by the gas current. There have been prior attempts to solve this problem by forming the electrodes as so called hollow box electrodes with double walls equipped with slots. It has also been conventional practice to form special grooves in the electroilter to remove dust therefrom. The present invention relates to a new, effective and inexpensive arrangement to solve the above mentioned problem.

The arrangement according to the invention relates to electrolters, preferably designed for a horizontal gas flow and having collecting electrodes in form of a number lof vertical plates for collecting precipitated dust, said plates being arranged on both sides of the discharge electrodes in rows parallel to the flow direction of the gas current. The new arrangement is characterized in that each of the rows of the collecting electrodes consists of a series of separate plates arranged close to each other, and being rotatable about their vertical shafts and movable into ltwo different working positions by suitable operating means. The plates are constructed in such a manner` that the plates 'in these two positions partly have exposed collecting surfaces facing the discharge electrodes and partly form closed vertical channels shielded from the gas current. The channels :are formed by two adjacent electrode units arranged close to each other, and enclose the dust which was deposited on the electrodes in a preceding working position. The dust, for example by vibrating the electrodes, may be caused to fall down in the channels without any risk vof its being picked up again by the gas current.

Other characteristics for the apparatus made according to the invention will be evident from the following description with reference to the accompanying drawings, wherein Fig. l is a horizontal section of ia part of an electrolter made according to the invention.

Fig. 2 shows in perspective a part fof `an electrode in form of a four-armed wing Wheel.

Fig. 3 is .a view similar to Fig. 1 showing a modified electrolter having electrodes which consist of a number of plates arranged on both sides of a common wall.

Fig. 4 is a view similar to Fig. l showing a modified electrolter having electrodes which consist of .a number of plates extending through the common wall.

Figs. 5a to 5e inclusive show a suitable operating means for the collecting electrodes.

In Fig. 1, an electrolter 1 having a main casing 2 and an inlet 3 operates to lilter Aa gaseous medium which is distributed at the inlet by means of ya number of distributing plates 4, and then passes the collecting electrodes 5 and the discharge electrodes 6 arranged in rows A, B, and C. In the embodiment shown in Fig. l, the collecting electrodes consist of vertical four-armed wing Wheels formed by two plane plates crossing each other at 2,884,087 Patented' Apr. 28, 1959 ICC right angles :and being rotatable about their vertical shafts 9-10 (Fig. 2) which are arranged in transverse alignment with the discharge electrodes 6. The wheels of the collecting electrodes are arranged to be rotatable a quarter of a turn at each operation by operating means, for example as shown in Figs. 5a-5e. Alternate wheels are turned to the left, and the intermediate wheels are turned to the right with a certain phase shift between the rotations to the left and to the right as indicated by the arrows. Between adjacent wheels of the collecting electrode in the same row there will occur closed spaces 7 which are shielded from the gas current. These spaces constitute vertical channels, in which dust being deposited on the electrodes at the preceding working position, for example by vibrating the electrodes, can be caused to fall down without any risk of the dust being picked up again -by the gas current. The precipitated dust 8 accumulates on the faces of collecting electrodes facing the discharge electrodes as shown in the row A. When adjusting the electrodes to the position shown in row B, the dust will be enclosed in the vertical channels and shielded from the gas current.

In Figs. 3 and 4, corresponding elements to those in Figs. l `and 2 have the same reference numbers. Figs. 3 .and 4 rpectively show ydiierent embodiments of the collecting electrodes. In Fig. 3 the collecting electrodes 12 Iare formed out of a number of plane plates arranged on both sides of a com-mon xed plate wall 13 which is parallel to the ow direction `of the gas current and coextensive with the central plane of the electrode. The plates are rotatably mounted along one of their edges at the plate wall 13 with its pivotal axis 11 in transverse alignment with a discharge electrode. The rows A and C on ione side and the row B on the other side illustrate the diiferent working positions of the pivoted plates, and the location of the channels for precipitated dust.

In Fig. 4 the rows A, C and the row B respectively illustrate in the corresponding manner the location of the channels for dust in the two working positions of the plates 14. The collecting electrodes are in this case formed out of a number of plates 14 which as indicated yat 15 lare pivotally mounted in slots made in the common wall 16. The two halves of the plates on both sides of the common wall will thus be pointing in diametrically opposite directions.

Figs. 5a to 5e show `a suitable yarrangement for operating the electrodes. In this arrangement, a certain phase shift is obtained between the clockwise and counterclockwise rotation. Thus, there is no chance for nter- -ference between the ends o-f the plates during operation. As shown :in Figs. 5a to 5e, the alternate electrodes 5 have cranks 18 interconnected by rods 19, :and the intermediate electrodes 5a have cranks 20 interconnected by rods 21. The rods 19 and 21 are connected to a crank 22 on an operator shaft 23 by means of connecting rods 24 `and 25 respectively. Rotation of the shaft 23 therefore alternately rotates the electrodes 5 and 5a a quarter Iof a turn in opposition to yone another.

While certain embodiments of electrodes and one form of operating mechanism have been herein illustrated and described, itis not intended to limit the invention to such disclosure, but changes and modifications may be made therein .and thereto within the scope of the following claims:

What I claim is:

l. An electrolter having discharge .and collecting electrodes mounted for horizontal gas ilow therebetween, said collecting electrodes being mounted on both sides of the disch-arge electrodes in rows having -a vertical center plane parallel to the ow direction of the gas, each collecting electrode comprising a series of separate flat vertically disposed plates mounted for pivotal movement about a asaltos? vertical axis in said center plane between clockwise and counterclockwise limit positions and extending angularly outward at both sides of the center plane, the free edge of each plate in one of its limit positions engaging the free'edge of an adjacent plate in its opposite limit position to form a closed channel between said plates and the Vertical center plane to shield one face of each plate from the gas flow and expose the opposite face of each plate to the gas flow, the free edge yof each plate in its opposite limit position engaging the free edge of an adjacent plate in its one limit position to form a diterent closed channel between the latter plates 'and the vertical center plane to shield the opposite face of the plate from the gas flow and expose the one face of each plate to the gas flow, and operating means to dispose said plates alternately in their opposite limit positions.

2. An electroflter according to claim 1 wherein every four plates of .each series are joined together at right angles to form a vertically-elongated four-armed wing wheel, said operating means being operable to rotate alternate wheels in each electrode clockwise :a quarter turn and the intermediate wheels in each electrode, counter clockwise a quarter turn with `a phase shift between said clockwise `and counterclockwise rotations.

3. An electrolter according to claim 1 including a plane fixed wall plate coextensive with said center plane of each collecting electrode and cooperating with said pivotally mounted plates to form said closed channels.

4. An electrolter according to claim 3 including means dening a vertical slot in said xed wall and characterized in that the pivotally mounted plates on opposite sides of the fixed wall are joined together to form a single plane element passing through said slot.

References Cited in the le of this `patent UNITED *STATES PATENTS 1,549,753 Edler Aug. 18, 1925 2,036,323 Engert Apr. 7, 1936 vFoREiGN'PATENTS i i i 90,856 Austria Jan. 25, 1923 

